The tendency of arch change in three-dimensional using the NiTi wire with reverse curve of Spee -an in vitro study
Chen Li, Zhang Ding, Fu Minkui
Objective This study was designed to observe the tendency of changes of arch in three dimension, when aligned by pre-shaped NiTi wire with reverse curve of Spee.Method Typodont with edgewise bracket and OPA-K pre-adjusted bracket were used to simulate clinical process. Arch changes before and after ligating the wire were measured by three-dimensional measure instrument.Results The rectangular pre shaped NiTi wire with reverse curve of Spee could increase the anterior arch width and decrease arch length, and this tendency was more striking in edgewise bracket than pre-adjusted bracket. Both round wire and rectangular wire could intrude incisors, extrude premolars, level the curve of Spee and decrease the arch length. Conclusion The result revealed that pre-shaped NiTi wire with reverse curve of Spee could level the curve of Spee and change arch length and width.